The present invention relates to a simulation system for use in testing motor controllers/drivers, and in particular to a simulation system that provides feedback simulating the loading of a mechanically loaded motor.
The operation of AC machines is determined by the frequency, amplitude and position of AC currents provided to the motor. To this end, most motor systems include a motor controller/driver that selectively controls the AC current to obtain the desired motor performance.
Testing the operation and performance of the motor controller/driver is typically done by either connecting the motor controller/driver to an actual motor and load, or through basic simulation of the inputs and output of the motor controller/driver. Both methods offer potential benefits and drawbacks. For instance, testing the motor controller/driver with an actual motor and load allows the actual motor response to be monitored. In particular, as the speed of the motor increases, the rotating magnetic field induces a back electromotive force (BEMF) that opposes the AC power provided by the motor controller/driver. Employing a mechanically loaded motor allows the motor controller/driver to be tested in the presence of this type of electrical response. However, during testing it is typically desirable to run the motor and load through failure scenarios in which the motor and/or load may be damaged. Because the test of failure scenarios can result in damage or destruction of the motor or load, this type of test can be prohibitively expensive.
Simulations provide an inexpensive alternative to mechanically loading the motor controller/driver directly. Simulations typically observe the waveforms generated by the inverter. However, this type of simulation does not include generation of the actual AC outputs provided to the motor or the electrical response generated by a mechanically loaded motor in response to the actual AC outputs. Thus, the simulation does not provide feedback opposing the output of the motor controller/driver as would happen in a motor controller/driver connected to a mechanically loaded motor.
A simulation system that overcomes these obstacles would therefore be desirable.